JPH03112020A - Rubber type key switch with light emitting function - Google Patents

Abstract

PURPOSE:To reduce any space in a key switch and to improve the operability thereof by forming the conductive portion of a movable contact of a ring-shaped conductive rubber, and forming each of stationary contacts on the site of a printed circuit board opposite to the rubber for uniting a light emitting and displaying function with a switching function. CONSTITUTION:A light emitting diode LED3 is solderingly fixed onto a printed circuit board 4 corresponding to the center of a button 1. Although the button 1 is moulded of a resin having excellent light transmissibility, its bottom face 1b is moulded in the shape of a sphere in order to expand the directivity of light emitted from the LED3. Then, a button head 1a is moulded for roughing the surface of a metal mould to be matted, with light traveling onto the surface of the button dispersed in order to improve the visibility of the button head. Furthermore, a contact unit is formed of a rubber contact 2 comprising a conductive rubber and an insulating rubber unitedly moulded with each other, and of electrodes formed on a printed circuit board. Depression of the button 1 accordingly causes the rubber contact 2 to be bent, whereby the conductive rubber contact 2b contacts the electrodes of stationary contacts 5a, 5b respectively for short-circuiting two circuits to be electrified. This can unite a light emitting function with a switching function.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rubber key switch having a light emitting display function and a switch function.

[Conventional technology]

Conventionally, the rubber type key switch with a luminescent display function has 1
The structure was such that the light-emitting diode for light-emitting display and the switch section for switch function were separated. For example 1
．． As shown in FIG. 5, a button 11 is arranged on a rubber contact 12 as a movable contact, a switch section is formed by fixed contacts 15a and 15b formed on a substrate 14, and a light emitting diode is placed in parallel with this switch section. 1-3 is soldered to a printed circuit board to form a discrete structure.

In this method, the illumination section by the light emitting diode and the button section to be operated are separated, resulting in a complicated design and requiring a large amount of space.

Further, as shown in FIG. 6, a gap is provided in the button 11, and the light emitting diode 13 is inserted into the gap, and the rubber contact 1 is inserted into the gap.
There is also a configuration in which it is arranged so as to cover 2.

[Problem to be solved by the invention]

In the above conventional technology, the light-emitting display section and the button section are separate, so the switch configuration is complicated and requires a large space.

An object of the present invention is to provide a rubber switch having a light emitting display function that is simple in structure and small in size, by integrating the light emitting display section and the button section, performing the light emitting and switching functions with the same button.

[Means to solve the problem]

The present invention is characterized in that the conductive part of the movable contact is formed of a ring-shaped conductive rubber, and the fixed contact has both electrodes mutually formed at a position on a printed circuit board facing the conductive rubber.

Further, the present invention is characterized in that both electrodes located on the printed plate are formed in the shape of a gear.

[Effect]

The light emitted from the light emitting diode passes through the transparent part of the rubber contact, is magnified by the spherical part on the bottom of the button and travels straight, and is scattered by the matte part on the button surface and illuminated. On the other hand, by pressing the button, the rubber contact bends, the conductive rubber part contacts the electrode part on the printed circuit board, and by short-circuiting both electrodes with the conductive rubber, switching of two circuits is performed. obtain. Also, by removing your fingertip from the button,
The button returns due to the restoring force of the rubber contact, and the operation is completed. In the shape of the fixed contact, gear-shaped protrusions are provided from both electrodes so that at least the tip of the protrusion corresponds to the position of the end surface of the ring-shaped conductive rubber. This ensures that no matter which end of the button is pressed,
The fixed contact comes into contact with the shoulder of the conductive rubber, ensuring reliable contact.

〔Example〕

An embodiment of the present invention will be explained in detail with reference to FIGS. 1 to 4. FIG. 1 shows a sectional view of a rubber key switch having a light emitting display function according to the present invention. A printed circuit board 4 that corresponds to the light emitting diode 3 at the center of the button 1.
Fix the solder on top. Note that when the button shape is relatively small, a chip-shaped light emitting diode is fixed.

Button 1 is molded from resin with excellent light transmittance.
In order to widen the directivity of the light emitted from the light emitting diode 3, the bottom part 1b of the button 1 is made spherical.

Further, in order to scatter light that has traveled to the button surface and improve visibility, the button head 1a is made matte by roughening the surface of the mold. Further, the contact is composed of a rubber contact 2 which is integrally formed of a conductive rubber and an insulating rubber, and an electrode formed on a printed circuit board. Since the rubber contact 2 has a structure in which an insulator 2a covers the light emitting diode 3, it is molded from a transparent silicone material that transmits light, and
The portion of the light emitting diode 3 through which light passes is made as thin as about 0.5 mm. Further, the conductive rubber 2b has a ring shape centered around the light emitting diode and is arranged outside the light emitting diode. A fixed contact 5a is placed on the printed circuit board facing the conductive rubber.

The electrode 5b is formed into a ring shape similarly to the conductive rubber 2b. Therefore, by pressing the button 1, the rubber contact 2 is bent, and the conductive rubber 2b is bent, and the fixed contact 5a, 5 is bent.
Continuity is achieved by contacting electrode b and short-circuiting both circuits, and when the fingertip is removed from button 1, the restoring force of the rubber contact causes the contact of the conductive rubber to separate from the fixed contact, opening the circuit and providing the switch function. It will be done.

FIG. 2 is a diagram showing the shape of the fixed contact and the arrangement of the contact to which the light emitting diode is attached. Fixed contacts 5a, 5
Although the function can be obtained even if the shape of b is simply ring-shaped as shown in the figure, when the operator presses the end of the button, the button 1 moves in an inclined state and conducts as shown in Figure 3. If the elastic rubber 2b is also tilted and comes into contact with the fixed contact, it will contact only the electrode 58 and the electrode 58
This means that the two electrodes will not be in contact with each other, and the two electrodes will not be short-circuited.

FIG. 4 is a diagram showing the shape of the electrode to prevent such malfunction. Incidentally, FIG. 4 is a view of the substrate of the printer 1 viewed from the front. The electrodes 5a and 5b are both ring-shaped, and conductive portions are formed with each other in the shape of gears at an angle of 11.25 degrees on concentric circles. The spacing between the conductor parts of both electrodes is the insulation spacing of both circuits, and when forming the electrodes with gold plating, it is 0.3 aw.
n, 0.5m when formed by conductive carbon printing
It is mu degree. Also, the position of the conductor part is determined by the conductive rubber 2b.
The conductor portion is formed so that both ends thereof in the width direction correspond to the respective tips of the conductor portion. That is, the portion indicated by the chain line in FIG. 4 corresponds to the conductive rubber 2b.

As a result, the button is tilted and pressed down, and the conductive rubber 2
Even if b is placed on the shoulder, contact is made in a circumferential manner, so both electrodes are short-circuited, and contact contact reliability is improved. In addition, in Figure 4, 6 indicates the soldering land of the chip light emitting diode, and 7 indicates the through-hole land, and the circuit is brought out on the back side of the printed circuit board so that it does not intertwine with the electrode circuit applied on the front side. It is something.

According to the present invention, it is possible to realize a small, thin, full-face rubber type key switch with a light-emitting display function, and by integrating the light-emitting display function and the switch function, it is possible to reduce space and improve operability. The effect of improving this can be obtained. Also,
By providing an optimal fixed contact shape for the ring-shaped movable contact, it is possible to securely contact the shoulder contact and soft bushing caused by pressing down the end of the button, improving contact reliability. It will be done.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a rubber key switch with a light emitting function showing an embodiment of the present invention, FIG. 2 is a front view showing the shape of fixed contacts on the printed circuit board shown in FIG. 1, and FIG. 3
The figure is a longitudinal sectional view of the key switch when the end of the button is pressed down, Figure 4 is a diagram showing the shape of the fixed contact of the present invention, and Figure 5 is a diagram showing the shape of the fixed contact of the present invention.
FIG. 6 and FIG. 6 are diagrams showing conventional embodiments. DESCRIPTION OF SYMBOLS 1... Button, 1a... Button head, 1b... Button bottom part, 2... Rubber contact, 2a... Part of insulating rubber, 2b... Part of conductive rubber, 3... ...Chip light emitting diode, 4...Printed circuit board, 5a, 5b...
Fixed contact, 6... Land, 7... Through hole land, 11... Button, 12... Rubber contact, 12b.
... Part of conductive rubber, 13 ... Light emitting diode, 14
...Printed circuit board, 15a, 15b...Fixed contact diagram (Ku) Fig. 3 (b) Fig. 4

Claims (1)

[Claims] 1. The conductive part of the movable contact is formed of a ring-shaped conductive rubber, and the fixed contact has both electrodes mutually formed at a position on a printed circuit board facing the conductive rubber. A rubber key switch with a light emitting function. 2. The rubber type key switch having a light emitting function according to claim 1, wherein both electrodes located on the printed circuit board are formed in the shape of a gear.